• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.9
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• pp.1175-1184
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• 2000

Effects of porous wind fences on the wind erosion of particles from a triangular sand pile were investigated experimentally. The porous fence and sand pile were installed in a simulated atmospheric boundary layer. The mean velocity and turbulent intensity profiles measured at the sand pile location were well fitted to the atmospheric boundary layer over the open terrain. Flow visualization was carried out to investigate the motion of windblown sand particles qualitatively. In addition, the threshold velocity were measured using a light sensitive video camera with varying the particle size, fence porosity $\varepsilon$ and the height of sand pile. As a result, various types of particle motion were observed according to the fence porosity. The porous wind fence having porosity $\varepsilon$=30% was revealed to have the maximum threshold velocity, indicating good shelter effect for abating windblown dust particles. With increasing the sand particle diamter, the threshold velocity was also increased. When the height of sand pile is lower than the fence height, threshold velocity is enhanced.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.740-745
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• 2000

Effects of porous fences on the wind erosion of sand particles from a triangular pile were investigated experimentally. The porous fence and sand pile were installed in a simulated atmospheric boundary layer. The mean velocity and turbulent intensity profiles measured at the sand pile location were well fitted to the atmospheric boundary layer over the open terrain. Particle motion was visualized to see the motion of windblown sand particles qualitatively. In addition, the threshold velocity were measured using a light sensitive video camera with varying the fence porosity ${\varepsilon}$. As a result, various types of particle motion were observed according to the fence porosity. The porous wind fence having porosity ${\varepsilon}=30%$ was revealed to have the maximum threshold velocity, indicating good shelter effect for abating windblown dust particles.

• Wind and Structures
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• v.22 no.5
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• pp.555-571
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• 2016

A hanging-type sand-retaining wall is a very common sand-blocking fence structure used to prevent sand movement. This type of wall is widely used along the Qinghai-Tibet and Gobi desert railways in Xinjiang, Western China. To analyze the characteristics of wind-sand flow fields under the effect of such a sand fence structure, a wind tunnel test and a field test were carried out. The wind tunnel test showed the zoning characteristics of the flow fields under the effect of the hanging-type sand-retaining wall, and the field test provided the sediment transport data for effective wind-proof interval and the sand resistance data in the front and behind the sand-retaining wall. The consistency of the wind-sand flow fields with the spatial distribution characteristic of wind-carried sand motion was verified by the correspondences of the acceleration zone in the flow field and the negative elevation points of the percentage variations of the sand collection rate. The spatial distribution characteristic of the field sand collection data further showed the spatial structural characteristic of the sandy air currents under the action of the hanging-type sand-retaining wall and the sand resistance characteristic of the sand-retaining wall. This systematic study on the wind-sand flow fields under the control of the hanging-type sand-retaining wall provides a theoretical basis for the rational layout of sand control engineering systems and the efficient utilization of a hanging-type sand-retaining wall.

• Journal of computational fluids engineering
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• v.20 no.2
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• pp.52-60
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• 2015

The objective of this research lies in the effect of installation parameters influencing on the wind proof performance of the coastal forest for damage prevention. The dissipation ratio of incident wind power is developed as an assessment index to make a lumped parameter study possible. From the real field data of East, West, and South Sea bounded on the Korean peninsula, single and double storied forests were modeled in three-dimensional shape with computer aided design, and so was done the artificial structures such as wind break, sand accumulating fence, and sand dune, etc With a commercial code ANSYS-CFX, the computational result from the comparison of dissipation ratio between single and double storied forest shows the effect of composition, and also the installation effect is investigated for artificial structures with optimal dimension of distance.

• Journal of The Geomorphological Association of Korea
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• v.17 no.1
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• pp.85-93
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• 2010

After the notorious Taean Oil spill in Dec. 2007, a series of sand fences made of fishing net were installed in front of foredune in Shindu dune area. This paper aims to understand the temporal and spatial characteristics of morphological changes of the beach and foredune. About 1m high sand accumulated around sand fences for the last 2 years. While a lot of sand deposited during the winter season (from autumn to spring), small amount of sand eroded and deposited during summer season (from spring to autumn) without big morphological changes. These results mean that sand fences help nature deposit sand near beach and foredune area.

• Journal of Environmental Science International
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• v.4 no.1
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• pp.29-40
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• 1995

Transport rate of windblown dusts such as soil, sand, snow is proportionate to $U*_^3 and U_*$, friction velocity, approximately to flow velocity of ink Therefore, through measurement and the flow velocity of wind, it turned out that, considering different velocity distributions caused by downstream distance and porosity percent, windbreaks with appropriate porosity rate to the Protection area should be chosen for the optimal fence effect. In the economic respects better are fences with gap of 20%~30%. Among the windbreaks to have the optimal fence effect.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.2
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• pp.71-84
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• 2021

Restoration of DMZ has come up with the discussion on the peaceful use of the DMZ and the conservation plan of the army. In this study, we aim to identify soil characteristics of 108 sites to figure out environmental conditions around the iron fence of DMZ where vegetation has been removed repeatedly. Based on the soil characteristics and climate variables, hierarchy clustering was performed to categorize sites. As a result, we categorized 108 sites into 4 types: middle elevation region, lowland, East coast lowland, other areas. Group of 'other area' is only high in nutrient and clay proportion. Others are in igneous rock and metamorphic rocks with a high proportion of sand and lower nutrients than the optimum range of growth in Korean forest soil. The middle elevation region has a high altitude, low temperature. The east coast lowland has a high temperature in January and low precipitation. The lowland has a low altitude and high temperature. This category provides the environmental condition around the DMZ fence and can be used to select plants for restoration. The restoration project around the DMZ iron fence should satisfy the security of military plans, which means that functional restoration is prior to ecological restoration such as vegetation management under a power line. Additionally, improvement of soil quality and surface stability through restoration projects is required to enhance the resilience of the ecosystem in DMZ.

• Journal of the Korean Geotechnical Society
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• v.28 no.9
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• pp.17-22
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• 2012

Wind blown sand is expected to disrupt the operation of the railway as the presented railway project in this paper consists of large earthworks in extreme topography of the mega dune fields. For successful railway construction in sand dune area, effective mitigation measure is the most important factor to protect the track from wind blown sand. The effective mitigation measure requires an integrated consideration of the earthworks geometry and the direct control measures such as fence system. Basically there's no perfect measure protecting railway track from wind blown sand, and it would be more economical and effective to develop robust, deliberate maintenance program for track and direct control measure on the basis of geo-morphological study. The purpose of this study is to identify the large scale geo-morphological terrains and specific sand dune morphology in the project area in UAE and estimate the direction and migration rate for sand dunes with the local variations in prevailing wind directions by undertaking literature review, and aerial photographs, satellite images, and ground studies.

• Korean Journal of Heritage: History & Science
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• v.55 no.4
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• pp.38-53
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• 2022

In this article, I have summarized and reviewed the concepts and terms surrounding the stamped construction technique, focusing on earthen walls in the Three Kingdoms period. This is because confusion is caused by defining the nature of the earthen walls by using various concepts and terms for each researcher regarding the substance and construction method of the earthen walls. The stamped earth method is a representative ancient civil engineering or construction technique in which a frame is made of plates to form a fortress wall, a fence, and the base of a building, and then soil or sand is poured into it layer by layer and then stamped with a bat to make it solid. Therefore, in order to prove that the earthen wall was built by the stamped earth method, evidence such as a narrow plate, a column for fixing it, long horizontal and vertical wood pieces to support the narrow plate, and traces of pounding the soil must be detected. However, in Korea, there are very few cases where such evidence has been fully excavated, so it is necessary to agree on how strictly the standards for the stamped earth method will be applied. The terms related to the stamped technique mobilized for the construction of the earthen walls were explained with actual examples by dividing the terms related to the concept into terms related to the principle and unit of the stamped plate, and the specific stamped technology. In particular, in Pungnabtoseong Earthen wall, a variety of typical and diverse methods of building the ancient stamped earthen wall were identified so that decisive data could be secured to understand the principles and techniques of the stamped earthen wall. In the future, a more general understanding of the stamped technique will be possible only when more evidence related to it is found in relics other than Pungnabtoseong Earthen wall.